PT-2026-39051 · Linux · Linux Kernel

Published 2026-05-08 · Updated 2026-05-26 · CVE-2026-43390

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the nstree component where permission checks for listing are insufficient. This allows privileged services to potentially see namespaces of other privileged services, which could lead to information leakage between them. The resolution involves implementing the may see all namespaces() helper function to centralize the policy for namespace visibility.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2026-43390

Affected Products

Linux Kernel

References · 13

• https://security-tracker.debian.org/tracker/CVE-2026-43390 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-43390 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-43390 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-43390 · Security Note
• https://git.kernel.org/stable/c/8d76afe84fa2babf604b3c173730d4d2b067e361 · Patch
• https://cve.org/CVERecord?id=CVE-2026-43390 · Security Note
• https://git.kernel.org/stable/c/0abd81645fc95ec6a9d4e4813000f22c5efc0ff4 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43390 · Vendor Advisory
• https://twitter.com/CVEnew/status/2052767693623980160 · Twitter Post
• https://twitter.com/dailycve/status/2059351285468483901 · Twitter Post
• https://twitter.com/hetmehtaa/status/2055151398283837677 · Twitter Post
• https://git.kernel.org/linus/8d76afe84fa2babf604b3c173730d4d2b067e361 · Note
• https://twitter.com/infoflowcloud/status/2052769634818887846 · Twitter Post